For a paint cans and other containers, it is of course desirable for the lid to be easily removable, but at the same time, a good, hermetic seal is often necessary until the lid has been removed. Additionally, there is usually a need for the lid to be reattachable to the container again.
To accomplish this, attempts have been made in the designing of plastic lids with circumferentially tear strips. Such lids can usually only be opened by removal of the circumferential tear strip, following which the lid itself may be removed. See, by way of example, Tupper U.S. Pat. No. 2,941,660; Carvalho U.S. Pat. No. 1,557,653; Blair U.S. Pat. No. 4,055,267; Giggard U.S. Pat. No. 4,165,018; Wortley et al. U.S. Pat. No. 4,362,253 and Curry U.S. Pat. No. 4,385,708.
The above are illustrative of various types of container lids which are openable by tearing, and in some instances folding of parts of the lid.
As a disadvantage of many tear-away lid designs, the lid is not very effective after opening for good reclosing of the container, especially when a tear strip is removed from a substantially 360.degree. section of the retaining flange of the lid.
In accordance with this invention, a container lid is provided which can produce a desired strong, hermetic seal until opened. Nevertheless, the container may be easily opended by means that provide disengagement of some of its retaining flange from the container, to permit such easy opening. However, upon reapplication of the lid to the container, it can still exhibit acceptable closing ability, so that the contents of the container do not spill or evaporate in between uses.
The container lid of this invention is particularly useful for large lids, for example paint bucket lids or lids for similar large containers or drums.